The Disqus embed currently loads wider than normal in Twenty Thirteen, Twenty Fourteen, and Twenty Fifteen themes. To fix this issue, you'll need to add a short line of code to your theme's CSS so it displays at the correct width. Twenty Sixteen does not require this fix. Follow the steps below:

1. In your WordPress Admin, go to your Appearance Editor screen and select the Stylesheet (style.css) document from the right sidebar. It should be selected by default.